Plays_with_Toys

Well, had a wierd batch of luck. I was shifting fine friday night, went to start the car on saturday morning and had something like 4 inches of play in the clutch pedal. I was already late to work so I drove off (yeah, it was a pain to shift, it would kick in gear a 1/2 inch off the floor). Checked later on and I had a very tiny pool of brake fluid in the clutch reservoir Poured more in, but I still have to pump the clutch up to get a good amount of resistance. I have come to the conclusion my clutch master cylinder has kicked the bucket...

So, on to my question: I have to bleed the clutch master cylinder in order to replace it, my chiltons says there is a bleed screw, but I don't see it. What should I be looking for, or is there another way to bleed it? Thanks!

mtnerman

hey .. this job is easy.. i replaced my clutch MC when i had my clutch problem.. remember that a lil while back? i got mine for advance auto was about 30 bucks. to bleed it you need to crawl under truck and bleed MC from your slave cylinder loacked outside the tranny near the starter.. i bled mine real well i did mine a lil longer to fully flush the system. i think i cranked and pumped 10 times.. till i was happy with it. while i did install of MC i also adjusted my free play on my clutch.. u can adjust the freplay with the rod on the MC that goes through the firewall. free play should be at about 1/8 of an inch... hope this all helps

john

StoryR

Yeah I just replaced my Clutch MC a few months ago...to be honest, if you are going to replace the MC, I would replace the slave cylinder as well. Only be cause they have a tendency to fail around the same time...that is what I did at least!

mtnerman

i second that story R .. i was in the mid of trying to find out why my clutch wouldn;t disengage.. i replaced SC then my MC like within 2 weeks of each other. now she shifts wonderful..with all new componets.. MC, SC and clutch..

StoryR

Yeah funny story acually, I replaced both SC and MC within two days of hard labor

So everything seemed great! I was so happy with the results, then about a week after I replaced everything, the clutch dropped to the floor again...I was so angry, I had no idea what went wrong.

So I tore everything apart again, and there was this little metal rod that feeds break fluid somewhere (I really had have no idea where). But it had a small crack in it, and break fluid was leaking at a very rapid pace...So I took it to a mechanic and said how much for the peice? He couldn't track one down, so I took it to a metal company near where I live and they made one for like $4!

Plays_with_Toys

Alright thanks guys! This is why I love yotatech, if I had just gone and done the MC, I prolly woulda lost the SC sometime soon. I will have to order that up.

I am curious though, how many miles did you guys get out of your trucks before they went out? I am at 95K... I have to get ready for my 100K maintenance soon, maybe this is part of it?

mtnerman

148,848 miles.. outlasted the tranny.. good ol asian toyota products..

mtnerman

i think plays with toys and i ahve the same truck.. expect my is super red 2.. i need to get a pic up.. i have a87 with the same S#@% on it too.. how rad.. how many mile su have on your toys?

Plays_with_Toys

94,940.5 miles Not bad for an 87 huh? Are you running NGK plugs too?

Oh and welcome to yotatech!

mtnerman

NGK plugs.. V power

StoryR

You know, I acually don't have all the mantinence records from the previous owner, but I am sure it had been done once before, I just hit 235,000 miles the other day, so I am guessing somewhere around 100-120k.

Plays_with_Toys

Well I appreciate the fact you guys responded, but now it seems it was unnecessary, unless I am mistaken...

On saturday shifting was bad, sunday, after filling up the reservoir and having to pump it up a few times it felt a little soft, but towards the end of the night it wasn't really flaky. And today, monday, I drove without any problems. The clutch play is about a 1/4 inchand it does seem just a tad softer, but it releases where it always did before, and I was even able to haul a couple hundred pounds of dirt on an errand. The replacement cylinder hasn't come in yet, but I did already pay for it, since it was a warehouse order. So should I go ahead and replace it as pre-emptive maintenance since I've paid for it, or just get a refund? Also, one other question about the slave cylinder: what will the car feel like or do if the slave cylinder lets out? In case this happens, I want to know how to detect it. Thanks!

EDIT: I forgot to mention one more thing that I found. Inside the reservoir is a plastic cap that seems to just be floating around when the car is off, in gear, without the clutch being depressed. I cannot remember ever seeing it floating like that, but I also can't remember if I ever opened up the clutch reservoir. I know that I opened up the brake reservoir a few times to check the fluid, and the fluid level, but don't particularly remember opening the clutch reservoir. So do you guys have a cap floating around, or is that supposed to be clamped down?

mtnerman

hey.. lets see.. umm keep the MC for the future i mean its only 30 bucks ya know? but hey just my take i would replace it since u have it but thats just me. the SC as far as detecting it going bad, would be REAL hard shifting. u can see it not move. the lil piston um if the piston won't move at all. the shiftin is the first thing u would notice. ok and lastly. the float in the Mc .. that is normal mine has it too. just a float im guessin for something what i dunno but bottom line i have a float and u should too

StoryR

For the SC going out! My gosh yes you would notice, I sure as hell did! The shifting gets REAL tough, and eventually, the clutch will just drop to the floor....
As for the floater, I believe it's only purpose is to see how much brake fluid is acually in the reservoir. Because DOT3 Brake Fluid is mildy transparent.

Plays_with_Toys

Ok sounds good! Thanks for the help, I'll keep the MC on a shelf until I have a good afternoon to change it. Or when I get bored and need an excuse to work on the truck.

bamachem

On my old 79 2wd 4speed, the MC/SC lasted until 290K!!!

Jackpot2

Bleeding the clutch hydraulic system is a worthwhile thing if you have trouble engaging gears. Its done down at the slave cylinder just in front of the transmission.

Since I have the piccys i might as well stick them here for you to see

slave cylinder:


Bleeding this involves a sucker who will sit in the drivers seat, a 10mm spanner, a piece of clear plastic tube (like off an oxygen mask) and an empty shampoo bottle or similar, and a bottle of new clutch fluid.
Seen as the slave may never have been bled the bleed screw nut will be fairly tight to open the first time so get out a 10mm socket and use the wrench to crack it open but close it immediately again. Now fit the plastic tube over the bleed screw-airtight. Run the tube down into the bottle and immerse the tube-end in an inch or so of new clutch fluid.
At the master cylinder take off the cap and fill the reservoir to the top. Go back to the slave and with your 10mm spanner, open the bleed screw (watch some fluid flow trickle down the tube twds the bottle), now tell the sucker in the seat to press down the clutch pedal and hold it down while you watch fluid shoot down the tube. Close the bleed screw again and get the helper to pull the pedal back up off the floor
Repeat the procedure between the devils above 3 times before you top up the fluid at the master cylinder to avoid sucking air down from the top.
Now do all that again ... open screw, floor pedal, close screw, lift pedal another 3 times then top up the fluid again. Do you see the cycle?
Repeat the cycle as many times as it takes until all the tube shows no signs of air when the pedal is floored. You should at some stage (while the pedal is floored and the screw is open) push the rod which comes out at the other end of the slave, back into the slave as far as it will go, then close the bleed screw and continue the process.
To finish, close the bleed screw, lift the pedal off the floor, top up the reservoir, cap it, and now try your clutch for firmness

Whatdyamean its still soft , get that master cylinder changed so!


master cylinder on my 2nd gen hilux surf:


Changing the master cylinder is done only when you have drained all fluid from the system at the slave bleed screw. Then you need to disconnect the rod you see in the picture from the clutch pedal assembly, nothing to complicated only no room for your head your arms your hands a light and those pedals down there! :
Now its back to the engine bay and take the heat sheild off the master cylinder (awkward to refit) and disconnect the line to the slave. Next is to unbolt the unit itself from the firewall (two 12mm bolts? only).
Your old cylinder should come out now (you did say you wanted it off didnt you ... oops). Bolt the new one in, connect the line, the heat shield, the clutch pedal assembly, fill with fluid, bleed below at the slave and now with new slave and master, you should find gearchanging a pleasure.

All that should take about as long to do as it took me to write this out too